Records of information may be stored and maintained in relational database systems. When new records or data sets are received to be stored in the relational database system, the new records may be compared against the old records to determine whether any of the new records match the old records. Where a new record matches an old record, it may not be necessary to store the new record in the relational database system. In some instances, a new record (or, for that matter, an old record) may include a typographical error resulting from a data entry or editing error. For example, the new record may include one or more deleted characters, one or more inserted characters, one or more substituted characters, one or more sets of transposed characters, or a combination thereof. Although the new record may actually be a duplicate of an existing record, the variation between the new record and the old record, however minor, may prevent the system from matching the new and old records. Accordingly, both the old record and the new record may be stored in the relational database system. Furthermore, the error in the new record may go uncorrected for some period of time.